Using the content property in CSS

Usage of content attribute in CSS

The content attribute in CSS is a very useful attribute, which is used to insert additional content in pseudo-classes.

The content attribute can generally only be used in pseudo-class selectors (such as ::before and ::after). It can be used to insert content such as text or images. We can achieve some very cool effects through the content attribute.

The following are some usages of the content attribute and specific code examples:

1. Insert text content

Through the content attribute, we can insert some new Text content to change the style of the element.

<style>
  p::before{
    content: "提示：";
    color: red;
  }
</style>

<p>这是一个段落</p>

In the above example, we inserted a pseudo element with the text content of "Prompt:" in front of the p element. By setting the content attribute, we can customize the style of the inserted text content.

2. Insert pictures

In addition to inserting text content, we can also insert pictures through the content attribute.

<style>
  .dialog-box::before{
    content: url('dialog-icon.png');
    display: inline-block;
    width: 20px;
    height: 20px;
    margin-right: 10px;
  }
</style>

<div class="dialog-box">这是一个对话框</div>

In the above example, we use the content attribute and set its value to the URL of the image to achieve the effect of inserting an image in front of the element.

3. Referring to the content of pseudo-elements

We can also reference the content of pseudo-elements through the content attribute.

<style>
  .tooltip::before{
    content: attr(data-tooltip);
  }
</style>

<button class="tooltip" data-tooltip="这是一个工具提示">按钮</button>

In the above example, we referenced the value of the data-tooltip attribute of the button element through the content attribute to achieve a tooltip effect.

4. Insert special characters

The content attribute can also be used to insert some special Unicode characters.

<style>
  .star::before{

    color: gold;
    font-size: 20px;
  }
</style>

<span class="star"></span>

In the above example, we use the content attribute and set its value to "ਭ" to insert the Unicode character of a star.

Summary:

The content attribute in CSS is very useful. It allows us to insert additional content in pseudo-classes to change the style of the element. Whether it is inserting text content, images, content referencing pseudo-elements, or inserting special characters, the content attribute provides us with many possibilities for custom styles. It is worth noting that the content attribute can only be used in pseudo-class selectors, and its value must be quoted. I hope that through the introduction of this article, you will have a deeper understanding of the usage of the content attribute in CSS.

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